Hayne

It's MarkB1983. Try private messaging him. Maybe he can help you.

Mmm. I'm not sure about this. But, Mark Byrne on here had the same sort of sound coming from his car. I heard it when he came over for me to do something to his car. I wasn't sure then either. But, maybe he has resolved it now. Its worth asking him. This was about 2 years ago. I'll dig out his username. Giles.

Hi Robert, Very unlikely to be the auxiliary transmission fluid pump as its not running very often,just when the gearbox changes from low ratio to high, and back again. Also, its unlikely you'd hear it as its inside loads of metal and bolted to the gearbox. Maybe it could be the hybrid coolant pump? Is your hybrid coolant topped up ok? (under the right hand engine cover in front of the inverter with the thick orange wires). Check this is full of coolant first. I've seen some threads talking about failing coolant pumps. Does this happen whenever the car is in READY mode, or just when it's hot? Cheers, Giles.

Awesome!! Glad you managed to repair it. Thanks for telling me about your success! And happy motoring! I have done 30k miles since replacing the bearings and it's still going strong. Car has done 187k now and drives perfect (although I will be selling it later this month as I fancy something different). Giles.

Mines now at 183k with no issues what-so-ever (apart from this pump). And the repaired pump is still working fine 2 years and 30k later.

Hi, Don't worry about driving your car with the failed transmission pump,it will be fine. I drove mine for about 6000 miles before I resolved the pump issue.The hybrid battery charged just the same, as this is from the alternator, so it will always stay at the same charge. The hybrid system still works, it is just limited in its functionality. After all, as there is no mechanical reverse gear on the car, the hybrid motors still let you reverse your car electrically. The only real difference is that the car can't change to its high ratio, as it needs the pump for this, so you cant go above 80mph. Also, you won't have much power from standstill until the engine revs, as it relies on electric power to give you the low end power (especially when setting off up a hill). Don't worry about it, just order your bearings continue to drive it and then fix it one weekend when you get round to it. Giles.

Yes, you shouldn't have any problems with your pump Krzysztof. Unfortunately mine is a 35300-30022, which will failed on me and all will eventually fail with this part. Don't know how well improved the 30 and 31 are, but I assume they have uprated bearings.

Hi Krzysztof, I am too in favour of changing the transmission fluid regularly, as there really is no such thing as 'sealed for life' as manufacturer's lead us to believe. However, just to clarify that the transmission fluid has no effect on the pump failure. The pump impellor and its housing is the only part that touches the transmission fluid and these never fail. The bearings run dry and are not submersed in the fluid at all and even if the fluid was thick, the pump would not be affected as it is on the impellor shaft mounted through the 2 bearings that moves and the strain would be through the additional current drawn from the speed controller, not any other part of the pump. The bearings only fail due to wear and eventually break down causing the impellor shaft to seize. Nothing you can do to prevent it happening, unless you change them. Regarding transmission fluid changes, you can only change half of it (about 4 litres) without removing the gearbox, so it will always be a half dirty. Oh and you are quite right; only use genuine Toyota ATF-WS. Its only £10 a litre anyway. Don't be tempted by cheap ATF !! Cheers, Giles.

Hi Muthanna, Not sure really, but preventative maintenance may prevent the car from stopping on the motorway! How man miles has yours done? My bearing failed at about 155k. I noticed it failing about 2 months before. If it was my car, I would change the bearings straight away. You may find your pump never fails. Bear in mind that if it does fail, you can still drive the car until you are ready to fix the pump. I drove mine for 5k before I worked out how to repair it. If you get the Hybrid System Overheating message on the dash when your foot is to the floor, then you know its time to replace the bearings. This is due to the car wanting to change ratio while retarding the power for a long time when the pump struggles, which causes the hybrid coolant to get hot (this should be a quick ratio change). Regarding the transmission fluid level'; are there any leaks on the gearbox? if not, then the level will be fine (if it was leaking it would be visible under the car). Cheers, Giles.

Hi Junhao, sorry to hear you're having this problem. On the positive side, it is repairable for only a few pounds, so not really a major problem. You don't need a new pump; it will only be the 2 bearings front and rear of the impeller shaft and it's not difficult to repair either. It is such a simple design.There's not really much to fail. No, the gearbox stays in place. Luckily, its quite easy to get to on a ramp. You will need 4 litres of transmission fluid (buy 5 in case), but only use genuine Toyota stuff. its only £10a litre, so best to use the right stuff. The CVT gearbox has an overdrive gear, meaning it has 2 ratios and a CVT variable gearing. The 1st gear goes up to 80mph and the second gear goes from 35mph to 155mph. The CVT is not actually in limp mode, it just can't change to the 2nd ratio (its the hybrid management that shows the fault and limits performance). The engine is an Atkinson Cycle engine with variable compression ratio (simulated by the valves), built for economy, so that's why it only has power at high revs. From low revs, the motor gives you the power to take off. That's why acceleration is slow from a standing start when this fault occurs. In fact, the Hybrid system id still operating, it just doesn't allow energy harvesting from coasting and braking, or all-electric drive. There is no reverse gear in our gearboxes. Reverse is done through the electric motor. Also, there is not starter motor either. The crank is turned by the same electric motors used for drive, so that's why it starts so smoothly and instantly. So, the Hybrid system is all working fine and charging from the alternator. Also, the air conditioning compressor is electric running from the 288V hybrid batteries. Its normal for the cruise control to stop working until the fault is cleared. I drove mine for 6000 miles before I worked out what was wrong with it. So no damage will occur to your gearbox; don't worry about that. Just use it until you fix it, but avoid starting off on steep hills going forwards, as you will find there isn't enough power to get you going!! If ever you do get stuck, reverse works up hills just fine!! Hope you get it fixed soon! Giles.

Carl, what's the HV battery conditioner you used? Sounds interesting...

Well Carl, I'm very impressed that you did this on your driveway without a ramp!! Very commendable. And without removing the wiring loom! This is a great example of proper DIY. I bet you are well chuffed with yourself! I know I was when I fixed mine. You are the 4th person to use my post to fix your car. And, it's good to see such great step-by-step instructions. Should help others in the future. You said that Lexus charge 7-800 for a pump; when I asked them for a new pump they wanted £3240 just for the pump (not including the gearbox). When Bruce did the same on his LS600h, Lexus quoted £8k for a new gearbox, so it's probably not much less for the 450h. Again, well done Carl. I bet that beer tasted just fine!

Lexus South Atlanta have an online catalogue which is useful for seeing exploded diagrams for all models. And its free to use. www.lexussouthatlantaparts.com Just find your vent and the exploded diagram should give you the info you need!

I would still read the codes first before going to Lexus. If you don't have a code reader, there are plenty of options out there for just a few pounds, then you will always have a reader to use whenever you need to. An ELM327 bluetooth interface (ebay £6) and a Torque app for android (£3) will cover most of your needs.

Hi Robert, I don't know if everything in your car would still work with the upgrade, but I've just checked in my boot and my amp has a Mark Levinson label on it, so I expect that you would need a Mark Levinson amp to go with your head unit. I would be surprised if your amp was compatible with the Levinson head, unless anyone else can enlighten me. Giles